Hot Start Solution fo my Truck

[Steeveedee]

For a few decades, my FIL's truck has had a problem cranking over when hot- just would not turn over, or turned over slowly. It was a known problem, and meant that each time his family went on a camping trip, if the truck got shut off, there was a minimum wait of at least half an hour before it would easily crank up again. It used to start OK, but at some point, that ability went away.

I know that people have gone to some lengths to get around the problem, including wiring in Ford solenoids to the start terminal. My wife inherited this truck 6 years ago when her father died.

I was working mucho overtime (in fact, I worked so much overtime that I invested the money, and retired at age 62). Now that I am retired, and got in a position where I had to depend on the truck for daily transportation instead of occasional use, I decided to track down the cause. Looking at other threads both here and on a Buick forum where I also am a member, I realized that this is a problem for a lot of older vehicles. It has been said by many that all you need are a new battery, new cables, and a good starter, maybe a heat shield, etc. I won't argue that a new vehicle doesn't have these issues. But some of the older ones do. I had to ask myself, “why”? I had done all these things already- new battery, new cables, new permanent magnet reduction gear starter motor, timing set properly (I put in an HEI, so points were eliminated, and shouldn't be the cause, anyway).

So, what was I left with? Hard cranking would be caused by voltage drop through the system, drawing large current. Looking at some threads, it occurred to me that I needed a better chassis to battery to body ground. I bought a couple ground straps and made sure that the block was grounded to the cab. The factory ground strap went from the cab to a valve cover bolt, which, IMHO, ain't good enough. I removed that strap and replaced it with one of the new straps, from the cab to the back of the passenger's side head. I sanded the head so that the strap had a good connection. The other strap was connected from the frame to the exhaust manifold on the driver's side (not original, but at this point I was grasping at straws). It started better, but the starter still had to grunt when hot. But I knew I was on the right track, because it improved.

It occurred to me that there was still too much resistance in the cranking circuit. In order to remove as much resistance as possible, I bought a new battery ground cable and ran it all the way to the starter, and put it under one of the starter bolts.

Truck now starts easily, hot.

Why?

Well, here is my thinking- when a vehicle is new, all connections are clean and tight. When the engine comes out for a rebuild, the following things can happen-

The block gets hot tanked, and painted nice
All the brackets and the bolts all get cleaned up and painted nice

Now, it all goes back together, and it's fine...for awhile, maybe the problem never crops up.

I worked for GM for awhile. When a vehicle is assembled, all the parts are clean, the bolt threads are only solvent-wetted, there is no corrosion, pretty much anywhere.

I live in an irrigated desert here in California, and had starting issues. If you live where the roads are salted, you can get (even ever-so-slight) corrosion between the parts. Given that the bolts attaching the brackets and such back during any maintenance, and especially at a rebuild, it is possible that they were just a little rusty from the hot tank and not being dried soon enough, whatever. Maybe the block rusted slightly in the threaded holes, again, slightly. Slightly is all it takes, when you are running 100-150 Amps through a normal starting circuit, which only increases when the resistance increases. Resistance also increases with temperature, which is why your truck starts cold, but doesn't when hot. Add the paint between the parts that you put on to make it look purty, and there you have it- and the threads maybe aren't clean like factory, to boot.

This worked for me. Maybe it will work for you.